Ironmaking system and ironmaking process of two-section downdraft bed

ABSTRACT

An ironmaking system and process of a two-section downdraft bed, including: a vertical melting furnace, where a basic combustor/gasifier is at the top, first and second inlets evenly along a side wall of the melting furnace below the basic combustor/gasifier, and the first inlet connected to coke powder/pulverized coal, air, and water vapor sources; a slag pool, at a bottom of the melting furnace; a vertical pre-reduction furnace, the top portion connected to the outlet of the melting furnace, third and fourth inlets on an upper portion of the pre-reduction furnace and connected respectively to a temperature-adjusting and tempering medium source and an iron mineral powder source, an outlet at a bottom of the pre-reduction furnace; and a separator, an inlet of the separator connected to the outlet of the pre-reduction furnace, and an outlet at a bottom of the separator connected to the second inlet through a pipeline.

BACKGROUND Technical Field

The present invention relates to the field of metal smeltingtechnologies, and in particular, to an ironmaking process of atwo-section downdraft bed.

Related Art

Information of the Related Art part is merely disclosed to increase theunderstanding of the overall background of the present invention, but isnot necessarily regarded as acknowledging or suggesting, in any form,that the information constitutes the prior art known to a person ofordinary skill in the art.

Currently, blast furnace ironmaking is a main method for producingsteel, and the predominance of the blast furnace ironmaking is unlikelyto be changed in a short term. The method is a continuous metallurgicalprocess for reducing iron ore into iron in a blast furnace, and asmelting process is as follows: Iron ore, coke, and a flux used forslagging are fed from a furnace top according to a prescribed ratio, anda charge level of a furnace throat is maintained at a certain height.The coke and the iron ore form an alternating layer structure in thefurnace. The coke combusts with oxygen in blown hot air to generatecarbon monoxide and hydrogen. Oxygen is removed from the iron ore in arising process in the furnace, to obtain iron through reduction, and theiron becomes a liquid at a searing temperature of more than 2000° C. Therefined liquid molten iron flows from a tapping hole, and forms castiron ingots through solidification. Impurities in the iron ore and theflux are combined into slags, and discharged from a slag discharginghole.

It can be seen that a large amount of premium coke is required in theblast furnace ironmaking. However, coke resources are increasinglydeficient, and prices of metallurgical coke are increasingly higher, butnon-coke resources that are abundant in reserves and that are cheapcannot be fully utilized in ironmaking production. To change thedependency of ironmaking on the coke resources, researchers havediscovered non-blast furnace ironmaking in different forms, and a modernnon-blast furnace ironmaking industrial system with direct reduction andmelting reduction as main parts is initially formed. The existingnon-blast furnace ironmaking technologies include a direct reductionmethod of gas reduction, a direct reduction method using a solidreducing agent, and typical melting reduction processes, for example, aCorex process, a Finex process, and a HIsmelt process. However, theforegoing processes have different problems respectively, for example,low reduction efficiency, a low waste heat recovery rate, and that somemetallurgical coke is still needed. An ironmaking process that has asimple process and low energy consumption is not achieved.

SUMMARY

To resolve the technical problem in the prior art, an objective of thepresent invention is to provide an ironmaking system and an ironmakingprocess of a two-section downdraft bed.

To achieve the objective, the present invention includes the followingtechnical solutions:

An ironmaking system of a two-section downdraft bed is provided,including:

a melting furnace section, vertically downward disposed, where a basiccombustor/gasifier is disposed at a top portion thereof, a first inletand a second inlet are provided below the basic combustor/gasifier, boththe first inlet and the second inlet are evenly provided along a sidewall of the melting furnace section, and form a tangent circle in themelting furnace section, the second inlet is located below the firstinlet, and the first inlet is connected to a coke powder/pulverized coalsource, an air source, and a water vapor source;

a slag pool, disposed at a bottom portion of the melting furnacesection, and equipped with a slag discharging device and a tappingdevice, where an outlet end is downstream of the slag pool;

a pre-reduction furnace section, vertically downward disposed, where atop portion thereof is connected to the outlet end of the meltingfurnace section, a third inlet and a fourth inlet are provided on anupper portion of the pre-reduction furnace section, an outlet isdisposed at a bottom portion of the pre-reduction furnace section, thethird inlet is connected to a temperature-adjusting and tempering mediumsource, and the fourth inlet is connected to an iron mineral powdersource; and

a first separator, where an inlet of the first separator is connected tothe outlet of the pre-reduction furnace section, and an outlet at abottom portion of the first separator is connected to the second inletthrough a conveying pipeline.

Carried by air and water vapor, coke powder/pulverized coal enters themelting furnace section from a side wall of the melting furnace section,to form a swirling flow in the melting furnace section, and rotationallymoves downward. A combustor jets a flame to the swirling flow, to igniteor gasify the coke powder/pulverized coal, to generate ahigh-temperature flame. Carried by the swirling flow, thehigh-temperature flame flows through a pre-reduced mineral powder fluidthat enters, and two strands of fluids with different movementvelocities meet, collide, and further, are rapidly mixed evenly.

Because the fluids spirally move downward, a time during whichpre-reduced iron mineral powder is in contact with a high-temperaturereducing gas is prolonged, so that a reduction degree of the ironmineral powder can be effectively improved, thereby improving anironmaking yield. In addition, the fluids spirally move downward, andplay a sound role in carrying the iron mineral powder, to effectivelyprevent the iron mineral powder from sedimentation in the meltingfurnace section, so that the iron mineral powder and a gas flow aremixed evenly, which is relatively beneficial to improve an ironmakingrate of the iron mineral powder.

An iron oxide in the iron mineral powder is reduced to generate molteniron, and the molten iron and slags fall into the slag pool, and aredischarged through the tapping device and the slag discharging device.

After being cooled to a proper temperature by a tempering medium thatenters through the third inlet, the gas flow flowing out of the meltingfurnace section enters the pre-reduction furnace section, and comes intocontact with the iron mineral powder fluid that enters, to pre-reducethe iron mineral powder. After the pre-reduction is completed, the ironoxide in the iron mineral powder mainly becomes FeO, and a part of theiron oxide is directly reduced into Fe. Separated by a separator, thepre-reduced iron mineral powder is conveyed to the melting furnacesection for high-temperature reduction. Because a pre-reduction step hasbeen performed, an ironmaking recovery rate of the iron mineral powdercan be significantly improved.

In some embodiments, a funnel structure is disposed at the bottomportion of the melting furnace section, and the slag pool is disposed atan outlet end of the funnel structure. The molten iron generated in themelting furnace section converges at the funnel structure, and flowsinto the slag pool through the funnel structure, to ensure that themolten iron flows out smoothly.

In some embodiments, the first inlet includes 2 to 8 inlets,circumferentially arranged along the melting furnace section.

In some embodiments, the second inlet includes 2 to 8 inlets,circumferentially arranged along the melting furnace section.

In some embodiments, the pre-reduction furnace section is connected tothe melting furnace section through an arc-shaped pipeline. Thearc-shaped pipeline can gently change a flow direction of a reducinggas, and has relatively small impact on an inner flow field of the gasflow. Through the arc-shaped pipeline, when flowing through thepre-reduction furnace section, the gas flow flowing out of the meltingfurnace section can play relatively good role in disturbing and carryingthe iron mineral powder added into the pre-reduction furnace section, toimprove a pre-reduction effect on the iron mineral powder.

In some embodiments, the ironmaking system of a two-section downdraftbed further includes a second separator, where an inlet of the secondseparator is connected to a gas outlet of the first separator through apipeline, a fifth inlet is provided on the pipeline, and the fifth inletis connected to a cold iron mineral powder source.

A gas flow with a relatively high temperature that is separated from thefirst separator flows through the fifth inlet, comes into contact withcold iron mineral powder added from the fifth inlet, heats the cold ironmineral powder, and carries the cold iron mineral powder to the secondseparator for gas-solid separation in the second separator. Thepre-heating of the cold iron mineral powder is relatively beneficial tosubsequent reduction ironmaking of the iron mineral powder.

Further, a solid outlet of the second separator is connected to thefourth inlet through a conveying pipeline, and a gas outlet is connectedto a first heat exchanger through a pipeline.

Because after the cold iron mineral powder is pre-heated, a temperatureof the gas is still relatively high, waste heat recovery can beperformed at a position of the first heat exchanger, to avoid heatwaste.

In some embodiments, the ironmaking system of a two-section downdraftbed further includes a pulverized coal coking furnace section and athird separator, where the pulverized coal coking furnace section isvertically disposed, a bottom portion of the pulverized coal cokingfurnace section is connected to the gas outlet of the first separator, asixth inlet is provided at a lower end of the pulverized coal cokingfurnace section, the sixth inlet is connected to a pulverized coalsource, and a top portion of the pulverized coal coking furnace sectionis connected to an inlet of the third separator.

A hot gas flow separated from the first separator can be utilized forheating and coking the pulverized coal.

Further, a solid outlet end of the third separator is connected to thefirst inlet. The separated coke powder is conveyed to the meltingfurnace section to participate in a reaction.

Further, a gas outlet end of the third separator is connected to asecond heat exchanger through a pipeline.

Waste heat recovery is performed through the second heat exchanger onthe hot gas flow separated from the third separator, to avoid heatwaste.

An ironmaking process of a two-section downdraft bed is provided,including the following steps:

entering, by coke powder/pulverized coal carried by air and water vapor,a melting furnace section from a side wall of the melting furnacesection, to form a swirling flow in the melting furnace section;

jetting, by a basic combustor/gasifier at a top portion of the meltingfurnace section, a flame inward to ignite or gasify a fluid, to generatea reducing gas;

jetting pre-reduced iron mineral powder into the melting furnacesection, to fully mix the pre-reduced iron mineral powder with a cokepowder/pulverized coal gas flow;

under the action of high-temperature reduction, reducing an iron oxidein iron mineral powder into an iron element, and melting the ironelement into molten iron at a high temperature; and

flowing, by a high-temperature reducing gas after the reaction, from themelting furnace section to a pre-reduction furnace section, andpre-reducing iron mineral powder jetted into the pre-reduction furnacesection; and conveying the pre-reduced iron mineral powder to themelting furnace section.

In some embodiments, the ironmaking process of a two-section downdraftbed further includes a step of pre-heating cold iron mineral powder byusing a high-temperature gas flow flowing out from the pre-reductionfurnace section.

In some embodiments, the ironmaking process of a two-section downdraftbed further includes a step of coking pulverized coal by using ahigh-temperature gas flow flowing out from the pre-reduction furnacesection.

In some embodiments, a temperature of a reaction in the melting furnacesection ranges from 1300° C. to 1700° C.

In some embodiments, a temperature of the pre-reduction furnace sectionranges from 700° C. to 1100° C.

In some embodiments, a circulating coal gas or a mixture of pulverizedcoal and a circulating coal gas is added into the pre-reduction furnacesection as a cooling and temperature-adjusting medium, and a proportionof a reducing gas in tempered gases is increased.

A mineral powder pre-reduction furnace section cooperates withpulverized coal coking/gasification, and a pulverized coal/water vaporvaporization medium or a circulating coal gas, together with thepulverized coal/water vapor, adjusts a temperature and is gasifiedsimultaneously. Cooling and pulverized coal gasification/coking areperformed simultaneously, to achieve tempering of the coal gas, andprovide more appropriate reduction conditions for subsequent mineralpowder pre-reduction. In this case, the coke powder and the mineralpowder are separated simultaneously, and are fed into the meltingfurnace section together.

The present invention has the following beneficial effects:

The present invention provides an ironmaking process of a two-sectiondowndraft bed, applicable to a melting furnace section and a mineralpowder pre-reduction furnace section. According to conditions requiredfor reducing iron mineral powder into molten iron, temperaturedistribution in a two-section reactor is controlled, a high-temperaturemelting reduction reaction occurs in the melting furnace section, andmolten iron is mainly generated from FeO. A pre-reduction reactionoccurs in the mineral powder pre-reduction furnace section, FeO or apart of Fe is mainly generated from iron mineral powder. The processachieves pre-reduction and melting reduction of mineral powder. Both ofthe two reactions are achieved in the downdraft bed, which is beneficialto maintain a uniform suspension state for mineral powder particles, andis beneficial to improve reduction efficiency. A process that iron oreis transformed into molten iron is completed within a same set ofdevices, complexity of the system is decreased, and an occupied area isdecreased.

Two temperature adjusting manners are provided for cooling andtemperature adjusting of a coal gas at an inlet of the pre-reductionsection. By using a circulating coal gas, the coal gas at an outlet ofthe melting furnace section enters the mineral powder pre-reductionfurnace section after being cooled by a cooling medium. Pulverized coal,or together with a circulation coal gas, is used as a cooling andtemperature-adjusting medium. A mineral powder pre-reduction furnacesection cooperates with pulverized coal coking/gasification, and apulverized coal/water vapor vaporization medium or a circulating coalgas, together with the pulverized coal/water vapor, adjusts atemperature and is gasified simultaneously. Cooling and pulverized coalgasification/coking are performed simultaneously, to provide moreappropriate reduction conditions for subsequent mineral powderpre-reduction. In this case, the coke powder and the mineral powder areseparated simultaneously, and are fed into the melting furnace sectiontogether.

Two distribution manners are provided for the coal gas after thepre-reduction. One is setting heat exchange of mineral powder in apre-heating swirling flow separator, to increase a mineral powdertemperature, which is beneficial to improve a pre-reduction level; andthe other is setting coking of pulverized coal, to enhance adaptivity tocoal types, and is particularly adapted to lignite or bituminous coalwith high moisture. Short-process smelting of steel can be achieved,leading to a broad application prospect.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings constituting a part of the present inventionare used to provide a further understanding of the present invention.The exemplary examples of the present invention and descriptions thereofare used to explain the present invention, and do not constitute animproper limitation of the present invention.

FIG. 1 is a structural schematic diagram of an ironmaking system of atwo-section downdraft bed according to a first embodiment of the presentinvention; and

FIG. 2 is a structural schematic diagram of an ironmaking system of atwo-section downdraft bed according to a second embodiment of thepresent invention.

In the figures: 1. basic combustor/gasifier; 2. first inlet; 3. secondinlet; 4. melting furnace section; 5. slag pool; 6. third inlet; 7.fourth inlet; 8. pre-reduction furnace section; 9. first separator; 10.fifth inlet; 11. second separator; 12. first heat exchanger; 13. coalgas outlet pipeline; 14. sixth inlet; 15. pulverized coal coking furnacesection; 16. third separator; and 17. second heat exchanger.

DETAILED DESCRIPTION

It should be noted that, the following detailed descriptions are allexemplary, and are intended to provide further descriptions of thepresent disclosure. Unless otherwise specified, all technical andscientific terms used herein have the same meanings as those usuallyunderstood by a person of ordinary skill in the art to which the presentdisclosure belongs.

It should be noted that the terms used herein are merely used fordescribing specific implementations, and are not intended to limitexemplary implementations of the present disclosure. As used herein, thesingular form is also intended to include the plural form unless thecontext clearly dictates otherwise. In addition, it should further beunderstood that, terms “comprise” and/or “include” used in thisspecification indicate that there are features, steps, operations,devices, components, and/or combinations thereof.

Embodiment 1

As shown in FIG. 1, a structure of a device (arrangement manner 1) of anironmaking process of a two-section downdraft bed includes a meltingfurnace section 4, where the melting furnace section 4 is a downdraftbed, a basic combustor/gasifier 1 is disposed at a top portion of themelting furnace section 4, a first inlet 2 of coke powder (pulverizedcoal) (air and water vapor) is provided on a side surface of an upperportion of the melting furnace section 4, and a pre-reduced mineralpowder inlet, that is, a second inlet 3, is provided at a specificdistance below the first inlet 2; and a mineral powder pre-reductionfurnace section 8, which is a downdraft bed, where a pre-heated mineralpowder inlet, that is, a fourth inlet 7, is provided on a side surfaceof an upper portion of the pre-reduction furnace section 8, and a lowerportion of the pre-reduction furnace section 8 is connected to an inletof a pre-reduced mineral powder separator, that is, a first separator 9.The melting furnace section 4 is connected to the mineral powderpre-reduction furnace section 8 through a slag pool 5. A cooling,temperature-adjusting, and tempering medium inlet, that is, a thirdinlet 6, is provided on a pipeline connecting the slag pool 5 and themineral powder pre-reduction furnace section 8. An upper outlet thefirst separator 9 is connected to an inlet of a pre-heating swirlingflow separator, that is, a second separator 11. A lower outlet of thefirst separator 9 is connected to the pre-reduced mineral powder inlet,that is, the second inlet 3. A cold mineral powder inlet, that is, afifth inlet 10, is provided at the upper outlet of the pre-reducedmineral powder separator, that is, the first separator 9. A lower outletof the pre-heating swirling flow separator, that is, the secondseparator 11, is connected to the pre-heated mineral powder inlet, thatis, the fourth inlet 7, and an upper outlet is connected to a coal gasheat exchanger, that is, a first heat exchanger 12 and a coal gas outletpipeline 13 sequentially.

The foregoing method of the ironmaking process of a two-sectiondowndraft bed (arrangement manner 1) includes the following specificsteps:

1) High-Temperature Melting Reduction

A basic combustor/gasifier combusts/gasifies coke powder (pulverizedcoal) (air and water vapor) that is fed, generates a high temperature ofaround 1600° C. and a reducing atmosphere, pre-reduced iron mineralpowder is mainly subject to a reaction in which FeO becomes molten ironin a melting reduction furnace, and the molten iron falls into a slagpool. The coke powder (pulverized coal) (air and water vapor) and thepre-reduced iron mineral powder are jetted in a four-corner tangentialor a six-corner tangential manner, which is beneficial to even mixing.

2) Mineral Powder Pre-Reduction

A high-temperature coal gas generated in the melting furnace sectionenters the mineral powder pre-reduction furnace section after beingcooled or tempered by a cooling/tempering medium, pre-heated mineralpowder is fed from above the furnace section, and the coal gas and thepre-heated mineral powder are mainly subject to a pre-reduction reactionfor generating FeO and a part of Fe from mineral powder. Thecooling/tempering medium is a circulating coal gas, or a circulatingcoal gas together with pulverized coal. Both of the two sections aredowndraft beds, which is beneficial to maintain a uniform suspensionstate for mineral powder particles, and improving reduction efficiency.

3) Pre-Reduced Mineral Powder Separation

The coal gas and the pre-reduced mineral powder enter an inlet of apre-reduced mineral powder separator, the pre-reduced mineral powder isseparated from below the separator, and enters the melting furnacesection through a pre-reduced mineral powder inlet; and the coal gas isseparated from above the separator.

4) Cold Mineral Powder Pre-Heating

The coal gas discharged from above the pre-reduced mineral powderseparator carrying cold mineral powder enters an inlet of a pre-heatingswirling flow separator, the coal gas exchanges heat with the coldmineral powder, and a temperature of the cold mineral powder isincreased, which is beneficial to improve a pre-reduction level. Thepre-heated mineral powder is separated from below the separator, andenters the mineral powder pre-reduction furnace section. The coal gas isdischarged from above the separator, and is discharged from a coal gasoutlet pipeline through a coal gas heat exchanger.

Embodiment 2

FIG. 2 is another implementation of this application. A structure of adevice (arrangement manner 2) of an ironmaking process of a two-sectiondowndraft bed includes a melting furnace section 4, the melting furnacesection 4 is a downdraft bed, a basic combustor/gasifier 1 is disposedat a top portion of the melting furnace section 4, a coke powder (airand water vapor) inlet, that is, a first inlet 2, is provided on a sidesurface of an upper portion of the melting furnace section 4, and apre-reduced mineral powder inlet, that is, a second inlet 3, is providedat a certain distance below the first inlet 2; and a mineral powderpre-reduction furnace section 8, which is a downdraft bed, where amineral powder inlet, that is, a fourth inlet 7, is provided on a sidesurface of an upper portion of the pre-reduction furnace section 8, anda lower portion of the pre-reduction furnace section 8 is connected toan inlet of a pre-reduced mineral powder separator, that is, a firstseparator 9. The melting furnace section 4 is connected to the mineralpowder pre-reduction furnace section 8 through a slag pool 5. A cooling,temperature-adjusting, and tempering medium inlet, that is, a thirdinlet 6, is provided on a pipeline connecting the slag pool 5 and themineral powder pre-reduction furnace section 8. An upper outlet of thepre-reduced mineral powder separator, that is, the first separator 9, isconnected to a pulverized coal coking furnace section 15, and a loweroutlet of the first separator 9 is connected to the pre-reduced mineralpowder inlet, that is, the second inlet 3. A pulverized coal inlet, thatis, a sixth inlet 14, is provided on a lower portion of the pulverizedcoal coking furnace section 15, and an upper portion of the pulverizedcoal coking furnace section 15 is connected to an inlet of a coke powderseparator, that is, a third separator 16. A lower outlet of the cokepowder separator, that is, the third separator 16, is connected to thecoke powder (air and water vapor) inlet, that is, the first inlet 2, andan upper outlet is connected to a coal gas outlet pipeline 13 and asecond heat exchanger 17 sequentially.

The method of another ironmaking process of a two-section downdraft bed(arrangement manner 2) in this application includes the followingspecific steps:

1) High-Temperature Melting Reduction

A basic combustor/gasifier combusts/gasifies coke powder (air and watervapor) that is fed, generates a high temperature of around 1600° C. anda reducing atmosphere, pre-reduced iron mineral powder is mainly subjectto a reaction in which FeO becomes molten iron in a melting reductionfurnace, and the molten iron falls into a slag pool. The coke powder(air and water vapor) and the pre-reduced iron mineral powder are jettedin a four-corner tangential or a six-corner tangential manner, which isbeneficial to even mixing.

2) Mineral Powder Pre-Reduction

A high-temperature coal gas generated in the melting furnace sectionenters the mineral powder pre-reduction furnace section after beingcooled or tempered by a cooling/tempering medium, mineral powder is fedfrom above the furnace section, and the coal gas and the mineral powderare mainly subject to a pre-reduction reaction for generating FeO and apart of Fe from mineral powder. Both of the two sections are downdraftbeds, which is beneficial to maintain a uniform suspension state formineral powder particles, and improve reduction efficiency.

3) Pre-Reduced Mineral Powder Separation

The coal gas and the pre-reduced mineral powder enter an inlet of apre-reduced mineral powder separator, the pre-reduced mineral powder isseparated from below the separator, and enters the melting furnacesection through a pre-reduced mineral powder inlet; and the coal gas isseparated from above the separator.

4) Pulverized Coal Coking

The coal gas that is discharged from the upper portion of thepre-reduced mineral powder separator and that carries pulverized coalenters a pulverized coal coking furnace section, at a temperature and anatmosphere provided by the coal gas, coke powder is produced by usingthe pulverized coal, a pyrolysis gas and the coke powder move upwardinto a coke powder separator. Coking of the pulverized coal is set, toenhance adaptivity to coal types, and is particularly adapted to ligniteor bituminous coal with high moisture. The coke powder is separated frombelow the separator, and enters the melting furnace section. The coalgas is discharged from above the separator, and enters a coal gas heatexchanger after flowing through a coal gas outlet pipeline.

The foregoing descriptions are merely preferred embodiments of thepresent invention, but are not intended to limit the present invention.A person skilled in the art may make various alterations and variationsto the present invention. Any modification, equivalent replacement, orimprovement made within the spirit and principle of the presentinvention shall fall within the protection scope of the presentinvention.

What is claimed is:
 1. An ironmaking system of a two-section downdraftbed, the system comprising: a melting furnace section, verticallydownward disposed, wherein a basic combustor/gasifier is disposed at atop portion thereof, a first inlet and a second inlet are provided belowthe basic combustor/gasifier, both the first inlet and the second inletare evenly provided along a side wall of the melting furnace section,and form a tangent circle in the melting furnace section, the secondinlet is located below the first inlet, and the first inlet is connectedto a coke powder/pulverized coal source, an air source, and a watervapor source; a slag pool, disposed at a bottom portion of the meltingfurnace section, and equipped with a slag discharging device and atapping device, wherein an outlet end is downstream of the slag pool; apre-reduction furnace section, vertically downward disposed, wherein atop portion thereof is connected to the outlet end of the meltingfurnace section, a third inlet and a fourth inlet are provided on anupper portion of the pre-reduction furnace section, an outlet isdisposed at a bottom portion of the pre-reduction furnace section, thethird inlet is connected to a temperature-adjusting and tempering mediumsource, and the fourth inlet is connected to an iron mineral powdersource; and a first separator, wherein an inlet of the first separatoris connected to the outlet of the pre-reduction furnace section, and anoutlet at a bottom portion of the first separator is connected to thesecond inlet through a conveying pipeline.
 2. The ironmaking system of atwo-section downdraft bed according to claim 1, wherein a funnelstructure is disposed at the bottom portion of the melting furnacesection, and the slag pool is disposed at an outlet end of the funnelstructure.
 3. The ironmaking system of a two-section downdraft bedaccording to claim 1, wherein the first inlet comprises 2 to 8 inlets,circumferentially arranged along the melting furnace section; or thesecond inlet comprises 2 to 8 inlets, circumferentially arranged alongthe melting furnace section.
 4. The ironmaking system of a two-sectiondowndraft bed according to claim 1, wherein the pre-reduction furnacesection is connected to the melting furnace section through anarc-shaped pipeline.
 5. The ironmaking system of a two-section downdraftbed according to claim 1, further comprising a second separator, whereinan inlet of the second separator is connected to a gas outlet of thefirst separator through a pipeline, a fifth inlet is provided on thepipeline, and the fifth inlet is connected to a cold iron mineral powdersource; and further, a solid outlet of the second separator is connectedto the fourth inlet through a conveying pipeline, and a gas outlet isconnected to a first heat exchanger through a pipeline.
 6. Theironmaking system of a two-section downdraft bed according to claim 1,further comprising a pulverized coal coking furnace section and a thirdseparator, wherein the pulverized coal coking furnace section isvertically disposed, a bottom portion of the pulverized coal cokingfurnace section is connected to the gas outlet of the first separator, asixth inlet is provided at a lower end of the pulverized coal cokingfurnace section, the sixth inlet is connected to a pulverized coalsource, and a top portion of the pulverized coal coking furnace sectionis connected to an inlet of the third separator; further, a solid outletend of the third separator is connected to the first inlet; and further,a gas outlet end of the third separator is connected to a second heatexchanger through a pipeline.
 7. An ironmaking process of a two-sectiondowndraft bed, comprising the following steps: entering, by cokepowder/pulverized coal carried by air and water vapor, a melting furnacesection from a side wall of the melting furnace section, to form aswirling flow in the melting furnace section; jetting, by a basiccombustor/gasifier at a top portion of the melting furnace section, aflame inward to ignite or gasify a fluid, to generate reducing gas;jetting pre-reduced iron mineral powder into the melting furnacesection, to fully mix the pre-reduced iron mineral powder with a cokepowder/pulverized coal gas flow; under the action of high-temperaturereduction, reducing an iron oxide in iron mineral powder into an ironelement, and melting the iron element into molten iron at a hightemperature; and flowing, by a high-temperature reducing gas after thereaction, from the melting furnace section to a pre-reduction furnacesection, and pre-reducing iron mineral powder jetted into thepre-reduction furnace section; and conveying the pre-reduced ironmineral powder to the melting furnace section.
 8. The ironmaking processof a two-section downdraft bed according to claim 7, further comprisinga step of pre-heating cold iron mineral powder by using ahigh-temperature gas flow flowing out from the pre-reduction furnacesection; or further comprising a step of coking pulverized coal by usinga high-temperature gas flow flowing out from the pre-reduction furnacesection.
 9. The ironmaking process of a two-section downdraft bedaccording to claim 7, wherein a temperature of a reaction in the meltingfurnace section ranges from 1300° C. to 1700° C.; or a temperature ofthe pre-reduction furnace section ranges from 700° C. to 1100° C. 10.The ironmaking process of a two-section downdraft bed according to claim7, wherein a circulating coal gas or a mixture of pulverized coal and acirculating coal gas is added into the pre-reduction furnace section asa cooling and temperature-adjusting medium.